Mathematics: Markov Processes . vols. 1 and 2. E. B. Dynkin. Translated from the Russian by J. Fabius, V. Greenberg, A. Maitra, and G. Majone. Academic Press, New York; Springer, Berlin, 1965. vol. 1, xii + 365 pp.; vol. 2, viii + 274 pp. Illus. $12 each.; Diffusion Processes and Their Sample Paths . Kiyosi Itô and Henry P. McKean, Jr. Academic Press, New York; Springer, Berlin, 1965. xviii + 321 pp. Illus. $14.50